Try Private Flying or the Instructors forum just above it.
I got shot down a few years ago for suggesting the idea of instructing on a PPL, just to do trial lessons. I totally get why, although people can get a little oversensitive to the detriment of their ability to explain why.
Don't let it bother you; the good thing is that at least you understand how better to choose your words. It is clear that you're hoping to fly for free (as in no expense to you) as opposed to fly for free (no expense to employer).
To instruct you no longer need a CPL, but you still need the theory side plus minimum hours. The amount of money you can spend in training, even without a CPL, is pretty high. You'd need to do a _lot_ of trial lessons to cover that.